EDM Cutting

EDM Cutting

EDM cutting, a process known as wire EDM, is the most effective method of making incisions into metal to form many different products. It is a process used to cut hard metals and other difficult materials. Instead of physically cutting or grinding, the material is eroded away using electrical discharge sparks that come from a wire made of brass, zinc, copper or tungsten. While there is not contact between the wire and workpiece, the sparks do all the cutting. Metals that are EDM cut must be electrically conducive and include aluminum, copper, zinc, tin, titanium, stainless steel, gold, lead, silver, iron, bronze and super alloys. Products like gears, robot parts, jewelry, stripper plates and molds are made by EDM cutting for the electronics, tool and die, aerospace, robotics, medical, automotive and metal sculpting industries. Complex patterns, intricate contours and delicate cavities are easily formed by rapid, controlled, repetitive spark discharges. EDM cutting can cut into materials that are as thin as a fraction of an inch to several inches. Originally intended as a manual process, innovations in metal forming technology transformed EDM into a fully automated, computer controlled process.

No preheating is necessary for EDM cutting, but since the sparks reach 10,000º C, chiller systems are a part of every process to control temperatures. EDM takes place in a bath of dielectric fluid, which washes away debris, conducts electricity between the electrode and the workpiece and prevents premature sparking. The pattern, which is often quite complex, is uploaded into software and then guided by a CNC (computer numeric controlled) machine or CAD/CAM, enabling close tolerances and a high amount of fine detail. The wire, usually made of brass, comes extremely close to touching the workpiece and leaves a small gap where the sparks create intense heat and vaporize the metal as the wire slowly moves forward. It is hollow, allowing high heat and sparks to shoot out the end. The workpiece is tightly clamped down and held in place while the wire moves in the path of the part pattern. The product has smooth, matte edges, no burrs and sharp corners that are slightly rounded. EDM part manufacturers are able to provide customers with low or high volumes of products that have close tolerances and a high degree of uniformity.